Inside pipe cutter



June lll, 1940. G. A. LowREY 2,204,091

INS IDE PIPE GUTTER Filed Feb. 13, 1939 2 Sheets-Sheet y1 49 l Z s if 5 5 52 5l ,l w i \m 7,7% 4l 39 5% I 4a V Q l r- 3? 35 30 ZI. 35

y al/ 2 e O 3% 27 @ww/m y I/ 2 GoeGE/Llowefr V or 4 4 c3433 Patented June 11, 1940 UNITED STATES 'earner orriics INSIDE PIPE CUTTER George A. Lowrey, Houston, Tex.

Application February 13, 1939, Serial No. 256,109

s i Claims.

Another object of the invention is toy provide pipe cutter of the character described embodying a cutter body, means for anchoring the cutter body to the pipe to be cut against downward movement and having cutter expanders thereabove; a tubular mandrel extended through the body and releasably Asecured thereto with outwardly movable cutters carried by the mandrel and movable into engagement with the expanders upon release and downward movement of the mandrel relative to the body and means for hold,- ing the cutters yieldingly against the pipe to be cut during the cutting operation whereby the bits ofthe cutters will be relieved of too severe stress during the cutting operation.

An important feature of the invention resides in the provision of a yieldable shock absorber adapted to hold the cutter bits yieldingly against the work whereby the cutters will be relieved, or permitted to'yield as the cutting operation proceeds;

With the above and other objects in view. the invention has particular relation to certain novel features of construction, operation and arrangement of parts, an example of which is given in this specification and illustrated inthe accompanying drawings, wherein:

Figure l shows a vertical sectional View of the upper endy of the tool.

Figure 2 shows a vertical sectional view of the lower end thereof.

' Figure 3 shows a cross sectional view taken on the line 3 3 of Figure 1.

Figure 4 shows a cross sectional view taken on the line 4 4 of Figure 1.

Figure 5 shows a cross` sectional view taken on the line 5 5 of Figure 2.

Figure 6 shows a cross sectional view taken on the line 5 6 of Figure 2.

Figure 7 shows a fragmentary vertical sectional view of the lower end of the tool with the guide shown in released and lowered position.

Figure 8 shows a side View of the complete tool shown in inactive or non-cutting position, and

Figure 9 shows a side view of the tool in cutting position in relation to the pipe to be out.

Referring now more particularly to the drawings wherein like numerals' of reference designate the same parts in each of the figures, the numeral 56' l designates a tubular cutter body having the external downwardly tapering flat faces l thereon, provided with the dovetailed ribs 3. On these faces are the wedge shaped slips having the dovetailed grooves Ei in their inner faces to receive the ribs 3 whereby said slips are slidahly anchored to said body. A tubular mandrel l works axially through the` body.

Screwed on to the lower end of the mandrel l there is a tubular guide 8 whose lower end is tapered or beveled at il so that it will readily enter the pipe to be cut. A tubular anchor lli is fitted around the mandrel and is screwed into the upper end of the guide il and may be secured against rotation thereon by the set screw ll. The upper end of the anchor l0 ahnte the annular external rib l2 on the mandrel and a nut i3 is screwed on to the rib with its lower margin surrounding and counters-ank into the upper end of the jaw anchor lil. The anchor ill has the side openings I4 therethrough whose lower ends extend slightly beneath the upper end of the guide B, as shown, in Figures 2 and C?. In these openings are mounted the jaws I5, whose upper and lower ends are inwardly shouldered as shown in Figures 2 and '7 and are surrounded by the lower end of the ange nut it and the upper end of the guide 8 as shown in said figures to limit the outward movement of the jaws, it; These jaws are normally maintained yicldingly in their outer positions by the coil push springs l?, lli interposed between the jaws and the mandrel as also shown in Figures 2 and 7.

Surrounding the mandrel. above the ilange nut i3 there is a sleeve ll threaded on to the lower end of which there is a tubular skirt ill whose lower end has the internal pitched ratchet teeth I9 adapted to engage over correspondingly pitched external teeth 2li of the jaws I5.

The sleeve Il has the vertically elongated side recesses 2l whose upper ends have the depending external stops 22 and whose lower ends extend beneath the upper ends of the skirt i0. T.n these recesses are the friction blocks 2li whose lower ends are inwardly shouldered and.` surrounded by the upper end of the skirt lil and whose upper ends are inwardly shouldered and extend up behind the corresponding stops 22 whereby the outward movement of the friction blocks 533 is limited. These friction blocks are seated against the coil springs '24, it which are interposed between them and the sleeve il, whereby they are normally held in their outer position in engagement with the stuck pipe 25 to be out. Links, as 26, have their lower ends pivcted to the upper end is the tubular cutter head 39.

of the sleeve I1 and their upper ends pivotally connected to the corresponding slips 4.

Screwed into the upper end of the body I there is a gland 21 whose upper end is enlarged forming a wear ring 28 on which is supported the antifriction ring assembly 29, said gland and rings surrounding the mandrel 1 and supporting the guide block 39 which also surrounds the mandrel and turns therewith during the cutting operation while the body I, gland 21 and wear ring 28 remain stationary asl hereinafter indicated.

A tubular housing 3l has its upper end secured to the guide block 33 and surrounds: the ring assembly 29, 28 and its lower end has an inwardly extended annular flange 32 which is countersunk into, and rotates independent of, the wear ring 28 as clearly shown in Figure l.

The block 38 has the inside vertical grooves 33 forming seats to receive the expander-Shanks 34 which are secured therein by the set screws 35. The cutter eXpanders 36 are formed integrally with the upper ends of said shanks. They are widened outwardly and seated in radial notches 31 in the upper end of the block 30 as also shown in Figure I as well as in Figures 8 and 9. The outer margins of the upper ends of the eXpanders are outwardly curved as shown more clearly in Figures l and 8.

The expanders are seated in the vertical external slots or keyways 38 formed in the mandrel 1 with the lower ends of the Shanks 34 seated on the lower ends of said keyways when the cutter is inoperative as illustrated in Figures l and 2.

Surrounding the mandrel above the expanders This head has an inside keyway 49 cut therein, extending from its lower end and terminating at the upper end 4I beneath theupper end of the head. A key 42 is located in said keyway, as well as in a coinciding keyway 43 in the mandrel, whereby the head 39 will rotate with the mandrel. The head1 39 is free to slide upwardly on the key 42 against the action of the spring 5I'.

The cutter head has in its lower end, vertically extending, radial slots 44 in which the cutters 45 are located. These cutters are mounted to pivot on the transverse pins 46 and their upper ends are extended above said pins and are seated on the coil springs 41 whereby the cutters are normally held retracted as shown in Figure 1. The lower ends of the cutters are formed with the outwardly directed bits 48. The lower ends of the cutters ride in the corresponding keyways or grooves 38 in the mandrel.

The upper end of the mandrel is connected to the tubular operating string 49 by means of the enlarged coupling 50. The operating string extends to the ground surface and forms means for operating the tool.

Surrounding the upper end of the mandrel and interposed between the lower end of the coupling 5I] and cutter head 39, there is a strong coil spring 5I which is placed under compression when the tool is assembled. Attached to the lower end of the coupling 50 and surrounding the spring 5I there is a tubular shield 52 whose lower end terminates a short distance above the upper end of the cutter head 39.

In operation, the tool is assembled as shown in Figures 1, 2 and 8, and lowered into the well and into the pipe to be cut. As the tool is lowered into said pipe, the friction blocks 23 will be in yieldable but frictional engagement with the inner wall of said pipe. When a point has been reached where it is desired to make a cut, the operating string may be turned to the right. The mandrel and the appendants thereon will turn with the string but the sleeve I1 and the cutter body, will be held against turning by the frictional engagement of the blocks 23 with the pipe 25. On account of the pitch of the intermeshing teeth I9, 2D, upon such rotation, said teeth will be disengaged and the mandrel will be permitted to move downwardly relative to the sleeve I1 and the slips 4. The body 2 will also move downwardly, the downwardly tapering faces 2 thereon causing slips 4 to move outwardly into engagement with the walls of the pipe 25 as shown in Figure 9, thereby anchoring the tool to the pipe to be out. Thereafter, the operating string may be gradually moved downwardly by suitable equipment at the ground surface provided for the purpose, thereby bringing the lower ends of the cutters 45 into contact with the outwardly curved faces of the expanders 3B and expanding the cutters to cause the bits 48 to come into cutting relation with the pipe to be cut and upon rotation of the tool, the pipe will be eventually severed as shown in Figure 9. As the cutter head 39 moves downwardly, its lower end will engage an upstanding stop 53 carried by the expander block 38 before the upper ends of the eXpanders come into contact with the upper ends of the keyways 38, so that the upper ends of the expanders will not be injured or distorted.

It is to be particularly pointed out that while the cutting operation is in progress, the spring 5I, being under compression, will act against the upper end of the cutter head 39 and will hold the bits 48 yieldingly against the work. Should the operating string 49 be lowered too rapidly so as to feed the bits to the work too fast, said bits may yield or should unusually hard material be encountered by the bits, they may yield and in any event they will be yieldingly fed to the work and will thus not be liable to be dulled or broken.

When a cut has been completed, the operating string 49 may be elevated, the springs 41 retracting the cutters. The teeth 20 of the jaws I5 being in the form of downwardly pitched ratchet teeth, will pass by the teeth I9, the springs -I6 yielding to permit this and will thereupon automatically engage with said teeth I9 and when the lower ends of the keyways 38 engage the lower ends of the Shanks 34, the cutter body I will be elevated, thus moving the slips 4 inwardly and releasing them from the pipe, whereupon the tool may be withdrawn from the pipe 25 or relocated therein for making another cut.

What I claim is:

l. An inside pipe cutter comprising a head adapted to be secured to an operating string, a cutter mounted on said head movable outwardly into active position and inwardly into inactive position, cutter actuating means for moving said cutter into active position upon downward movement of the head relative to the actuating means, said cutter actuating means including yieldable means for holding the cutter yieldingly against the work and means effective to lock the head against subsequent downward movement relative to the cutter actuating means, upon upward movement of the head.

2. An inside pipe cutter comprising a cutter head adapted to be secured to an operating string, a cutter mounted on the head and outwardly movable relative thereto into active position and inwardly movable into inactive position, means normally holding the cutter in said inactive position, cutter actuating means including means for anchoring the device to the pipe to be cut and provided to move the cutter into active position upon downward movement of the head relative to said actuating means whereby the cutter will be moved into cutting relation with the pipe, yieldable means acting against the head for holdingv the cutter yieldingly in cutting relation with the pipe and means responsive to upward movement of the head relative to the pipe for temporarily holding the head against subsequent downward movement in the pipe relative to the cutter actuating means.

3. An inside pipe cutter comprising a mandrel adapted to be secured to the lower end of an operating string, a cutter head slidable on the mandrel, a cutter mounted on the head and movable outwardly into active position in cutting relation with the pipe and movable inwardly into inactive position, a yieldable member tending to resist upward movement of the head on the mandrel and thereby holding the cutter yieldingly in cutting relation with the pipe, cutter actuating means for moving the cutter into active position upon downward movement of the head, means for anchoring the cutter actuating means to the pipe and means effective, upon subsequent upward movement of the head to secure the head against subsequent downward movement with respect to the actuating means while the pipe cutter remains in the pipe.

4. An inside pipe cutter adapted to cut by rotation shaped to enter a pipe in a well and comprising a cutter head adapted to be secured to an operating string, a cutter mounted on the head movable outwardly into active position in cutting relation with the pipe and movable inwardly into inactive position, cutter actuating means ior moving the cutter into said active position upon downward movement of the head relative to the actuating means, yieldable means acting against the head and eiective to hold the cutter yieldingly against the work.

5. An inside pipe cutter adapted to cut by rotation shaped to enter a pipe in a well and comprising a cutter head adapted to be secured to an operating string, a cutter mounted on the head movable outwardly into active position in cutting relation with the pipe and movable inwardly into inactive position, cutter actuating means i'or moving the cutter into said active position upon downward movement of the head relative to the actuating means, yieldable means acting against the head and effective to hold the cutter yieldingly against the work and means effective to lock the. head against subsequent downward movement relative to the cutter actuating means, upon upward movement of the head.

GEO. A. LOWREY. so 

